STEREOTYPED MOTOR PROGRAMS IN HUMAN ESCAPE: QUANTIFYING THE ACTION SPACE OF HUMAN DEFENSIVE BEHAVIOUR USING WIRELESS VIRTUAL REALITY

Escaping imminent danger requires rapid action under extreme time pressure, yet the space of movements available to the human body is vast. In non-human animals, escape strategies are shaped by neural, biomechanical, and ecological constraints, resulting in species-specific patterns. In humans, ethical and practical constraints have until recently hindered the investigation and quantification of escape movements, such that their organising principles are commonly extrapolated from other, mostly quadruped, species. Here, using wireless virtual reality (W-VR) in a large physical space, we capture unconstrained whole-body kinematics of human escape from biologically relevant threats. We discover that human escape behaviour is organized within a constrained action space shaped by threat and context. The dominant motor program consists of a stereotyped sequence: head orientation toward the threat, body rotation until facing away, and escape with the ipsilateral foot first. Alternative variants include turning away from the threat, backward movement, and misdirected flight. Certain escape patterns and kinematic features reduce success, whereas specific preparatory adjustments enhance it. Our findings demonstrate that human escape patterns cannot be extrapolated from other mammals, provide a foundation for probing the neural mechanisms of escape, and enable investigation of potential disruptions in clinical conditions.